<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        h1{
            color: red;
            color: #00ff00;
            color: #00f;
            color: rgb(255,0,0);
            color: rgba(255,0,0,0.5);
        }
        div{
            width: 200px;
            height: 200px;
            background-color: purple;
            /*设置背景图片*/
            background-image: url("../day01/a.jpg");
            /*设置背景图片尺寸: 宽 高 */
            background-size: 100px 100px;
            /*设置禁止重复*/
            background-repeat: no-repeat;
            /*设置背景图片位置*/
            /*background-position: 50px 100px;*/
            background-position: 50% 50%;
        }
    </style>
</head>
<body>
<div>ABCD</div>
<h1>颜色测试</h1>
</body>
</html>